1. Technical Field
The present invention relates to attaching devices and projection display devices etc.
2. Related Art
In recent years, in electronic equipment such as a cellular telephone, a personal computer, a car navigation device, a ticket-vending machine, and a bank terminal, a display device having a position detecting function, the display device provided with a display section having a front face on which a touch panel is placed, has been used. This display device allows the user to point at an icon or the like in a display image or input information while referring to an image displayed on the display section. As a position detecting method using such a touch panel, a method using a resistive touch panel or a capacitive touch panel, for example, has been known.
On the other hand, the display area of a projection display device using an image projection device (a projector) is wider than that of the display device of the cellular telephone or the personal computer. Therefore, it is difficult to realize position detection by using the above-described resistive touch panel or capacitive touch panel in the projection display device.
Moreover, as a method for realizing position detection in the projection display device, there may be a method by which a position detecting device which can optically detect the position of an object is built into a housing of the image projection device. However, with this method, there is a possibility that the housing of the image projection device increases in size, resulting in an increase in the cost of parts, for example.
Furthermore, as an existing technique related to a position detecting device for a projection display device, the techniques disclosed in JP-A-11-345085 and JP-A-2001-142643, for example, have been known. However, such a position detecting device has problems such as an undesirably large system.